How do you YS experts store your engines for the winter? Is it possible to get enough oil in the engine to protect the bearings while the engine is in the plane? If so how is it done? I must be doing something wrong as I have been using Mobil 1 in my OS engines and have had to replace bearings in a 61 and 91 2 cycle this summer

I feel sorry for you guys "up north". I store my engines on my planes, 'cause here in "Dixie" we fly all year long. The coldest days we ever get are maybe in the mid-40's, very seldom gets colder than that. And on the cold days the air is so much denser, the planes fly so well, we actually look forward to it.

If I happen to have an engine that I'm putting away for a period of time, I usually run it dry first. After removing all the fuel from the tank, I connect the glow igntor, start the engine, and let it run until it quits. I think the nitro in the fuel has a corrosive effect if left in an engine, so I like to get it out. Then put a little after-run oil, or better yet Marvel Mystery Oil, in the carb and rotate the engine several times to spread it around.

It's my opinion that a lot of damage that is done to engines that have been stored is done not when it's stored, but when it is started again after storage. Oil it good again before you try to run it for the first time in the spring, so you don't start it up with the bearings dry.

David

I never use after run oil. I just run the engine dry after the last flight of the day. The biggest problem I ever had in the spring was old fuel being gelled in the regulator passages.

The after-run oil is purely optional, but the Marvel Mystery Oil won't cause you any problems at all, and will coat the internal parts a bit to keep humidity from attacking the parts. The aluminum parts of the engine are pretty well invulnerable, but the bearings themselves, the little balls, are prone to get small spots of rust and corrosion that will cause them to fail at high speeds. I just don't like to leave an engine for any length of time with no protection on the parts.

David

Whatever you decide to do, keep in mind that if you use non-synthetic oils they will destroy the silicone parts in a YS engine.

Appreciate the info! Big question is how do you get oil to the crank bearings? Engine does not have a crankcase vent that I am aware of.

The intake tract goes into the crankcase unlike other 4 stroke engines. The YS uses the crankcase pressure to supercharge the engine.

Hi Petec
How do you run the engine dry ? just disconnect both lines ( fule and the return line ) and run at idle ?

Just the fuel line. no need to disconnect the pressure line

You don't need to disconnect either line. As a matter of fact, I'd recommend leaving them both connected so that you get the tank completely empty. Put your throttle on idle or a click above, connect the glow ignitor, and start it.

OPTIONAL: Once it quits, if you want to store it, squirt whatever kind of oil you prefer directly into the carb opening, and then rotate the prop several times to distribute it a little bit.

David

I store my engines on the plane, run the fuel out and put them away. I don't use ARO. Then again, even in the winter it's usually never more than a week between flying days. Don't you guys know, God made snow so that airplanes with skis would have something to land on and take off from. You do have skis, don't you?
Paul

Here in Dixie we pull our skis behind a boat that is loaded with one or more (depending on your marital status) tanned, bikini-clad Southern Belles. Oh snap, now I've gotten myself all flomigated!

David

Ditto to what Daivid said!!!

Don't use Marvel's Mystery Oil in a YS engine. It has petroleum in it. If you are going to use after run oil make sure it is synthetic.

I've got a bottle of AMSOil synthetic pre-mix 2-cycle oil. Is this crap bad for the YS engines? It's really blue in color which kind of bugs me. Got it from the hobby shop, but the thought of it going through the regulator kind of bugs me.